Tripp Lite SU60KX Fan Control Circuit, Located on NH-SYS-M board System MCU and Control Circuit

2 Theory of Operation (continued)

2.12 Fan Control Circuit

Located on NH-SYS-M board (System MCU and Control Circuit)

		+12VS	CM123	G1					5VS
										RM7
	9	UM8A								10K
FAN-C							(18)	RM6
	1		16	FAN-SPEED-C						FANLOCK_C
(17)								10K
										CM136
	8									104
		G1		RM161	5VS	CM124	G1	RM162	G1
				5VS	14		+12VS			UM8E
				(143) FAN_A	1	UM12A 3
					+		4	13	5	12	FAN_SPEED_A
	FANLOCK_A (19)			FAN_ON	2-	4081		UM8D		ULN2003A
								ULN2003A
					7
	RM163							RM164
5VS				DM32
						G1		5VS		DM33
			DM34
							(48) FANLOCK_B				FAN_LOCK_B
	RM166
5VS				FAN_LOCK_A
								RM167
				RM168			+12VS
			5
										UM8G
			UM12B 4			8	106	11	7
	FAN ON		6 4081			UM12C				10	FAN SPEED B
				G1		9 4081		UM8F		ULN2003A
				CM127				ULN2003A

Located on NH-SYS-P board (Auxiliary Power for System, Detect Circuit for Voltage and Current)

	+12VS	DP5	CNP16
			1
CP96	RP194		2
			3
G1		D	FANLOCK C
	G		QP14
FAN SPEED C			DP6
		S

G1

Located on NH-SYS-S or NH-SYS-SA board (Driver Circuit for Bypass SCR)

		TOFAN
	+12VS		DSA10	CNSA4
				1
CSA16	RSA21			2
				3
G1		G		D QSA9
FAN_SPEED_A
				S

		+12VS	DSA11	CNSA5
				1
	CSA17	RSA22		2
				3
FAN_LOCK_A	G1		D	FAN_LOCK_B
		G		QSA8
	FAN_SPEED_B
			S

G1 G1

(a)Fan C is located at the rear panel of the power module’s input EMI filter. Fan A and Fan B are both located at the heat-sink for bypass SCR.

(b)MCU controls fan C via FAN-C (17).

(c)MCU detects a fan C failure via (18).

(d)When in bypass mode, FAN_A (143) will be high to control fan A; fan B will be off. If fan A experiences a failure, fan B will turn on.

(e)MCU detects a fan A failure via FANLOCK_A (19).

(f)MCU detects a fan B failure via FANLOCK_B (48).

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